Topical drugs, particularly those employed for the purpose of restoring hair growth, are most effective when delivered to the scalp and, even more importantly, to the hair follicles. In circumstances where the scalp is hairless, direct application of such drugs over a broad surface can be achieved by a multitude of simple means such as painting or wiping. Many applicators have been developed which would satisfy this requirement. For example, U.S. Pat. No. 4,572,689 issued to Chernack on Feb. 25, 1986 discloses a disposable applicator which employs a bristle brush to paint a liquid product onto a surface. Other applicators which use porous materials for applying liquids have also been disclosed. disclosed. U.S. Pat. Nos. 2,913,747 issued to Hempel on Nov. 24, 1959; 3,271,810 issued to Raffe on Sept. 13, 1966; and 4,218,155 issued to Weidner on Aug. 19, 1980 employ felt, rubber or plastic sponge, and open cell plastic foam, respectively, as the applicator surfaces.
However, assuming the drug is effective and that the subject using the drug is only partially bald, a means to efficiently apply the drug to the scalp rather than existing hair is highly desirable. The presence of hair requires the drug be delivered down through the hair and around the hair shafts. This condition may be satisfied by a dispenser which presents the dispensed liquid from a small opening at the tip of an extension from the body of the container or reservoir. Such dispensers are disclosed in U.S. Pat. Nos. 2,896,237 issued to Owens on July 28, 1959 and 3,777,949 issued to Chiquiari-Arias on Dec. 11, 1973.
In reality, varying degrees of baldness will be present with different subjects at the commencement of the treatment. Also, as the treatment progresses, each particular subject will be required to treat the scalp with varying degrees of hair present.
The application of a hair restoration drug is basically a "blind" operation in that the subject may often not be able to see the actual application of the drug, i.e., at the back of the head or under the hair. The application will be accomplished primarily by feel, whether by the actual contact of the applicator or by the cooling effect of the liquid applied. Therefore, a quick feedback between the act of compressing the reservoir and the presence of liquid on the scalp is very important. Porous applicator surfaces delay the feedback by requiring the applicator to become saturated. Additionally, some rigid porous applicators will retain a quantity of the liquid which is essentially unavailable for dispensing.
As the human scalp is sensitive, the applicator surface should be smooth and low friction. It should also have no jagged projections such as may be left at the break away tips of dispensers such as disclosed in U.S. Pat. No. 3,777,949 issued to Chiquiari-Arias on Dec. 11, 1973.
Further, the applicator should resist soiling by hair and scalp.
In light of the above, a principal object of the present invention is to provide a simple dispenser for the application of a liquid product, e.g., a hair restoring drug, which will enable the user to accurately and comfortably apply the liquid product to both broad surfaces or specific points.
Another object of the present invention is to provide an inexpensive disposable dispenser which is fully sealed until the time of use.
A further object of the present invention is to provide a dispenser which permits the user to effectively treat the scalp in the presence of hair with minimal disruption of the hair style as well as quickly treat broad areas of the scalp where little or no hair is present.